Magnetic core sorting device



Oct. 28, 1958 M. A. ALEXANDER ETAL 2,858,018

MAGNETIC com; soRTING DEVICE Filed sept. 2. 1954 FEEDER SELECTOR F ROM o READING con. l

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m 46 im INTEGRAT fir/m06 IN V EN TORS United States Pater 2,858,018 Patented Oct. 28, 1958 hice MAGNETIC CORE SORTING DEVICE pforzton, Los Angeles, Calif., a corporation of New Application September 2, 1954, Serial No. 453,862

l4 Claims. (Cl. 209-74) This invention relates to test equipment and, more specically, to an improvement to assorting mechanism employed in test equipment for separating the objects being tested into their proper categories.

In the Proceedings of the I. R. E. for October 1953, page 1407, Dr. lan A. Rajchman in an article entitled A Myriabit Magnetic Core Matrix Memory describes a memory made of magnetic cores the sizes of which are on the order of .O54 inch O. D., .034 inch I. D., and 0.106 inch in height. Also shown and described is an automatic cor-e tester This is a device for picking up these cores, passing them one at a time through a zone during which they are electrically tested, and then accepting or rejecting them in accordance with the results of such test.

In present practice, a word made up of a plurality of binary digits is stored in a magnetic memory by using a different magnetic core plane to store each binary digit. Each core plane consists of a two-dimensional array of columns and rows of cores. Each column of cores in a plane is driven by a separate column coil and each row of cores in a plane is' driven by a separate row coil. Other windings are used for reading and/ or inhibiting the cores of a plane, as required. It will be appreciated that in any one plane the cores employed should have substantially uniform characteristics. This requirement is established by the manner of driving these memories which, as has been described in the literature, consists of simultaneously applying current drives to the row coil and column coil inductively coupled to the core either in which information is desired to be written or from which it is desired to read information. Presumably, the cores all have substantially rectangular characteristics. However, the coercive force which must be overcome in order to drive a core can vary, and if there is too much variation a core can conceivably be driven by the excitation of the row coil or column coil alone to which it is coupled. By the same token, some cores can Ibe driven by the double excitation and others, having a sufficiently large coercive force, cannot be so driven.

Another consideration in the construction of core memories is the voltage to be derived when a core is to be driven for the purpose of reading. It has been established that unwanted signals are induced in the reading coil of a memory by the half drives to cores which are not selected for reading. Thelarger the memory the greater the number of these half-driven cores and, accordingly, the greater the unwanted signal induced in the reading winding. The output from a driven core should' be sufliciently large to be distinguishable above the unwanted signal voltages from the various cores.

There are a large number of other4 considerations involved, but the ones so far described are some of the major considerations in establishing that the cores employed in any two-dimensional memory plane should be selected to have substantially uniform characteristics. I In the machine shown and described in the article, cores are either selected or rejected. In order to ob- 2. tain reasonably uniform cores for employment in a memory, the selection must be made within a very narrow band, namely, the variations in requirements for the selected cores are not too great. This results in the rejection of cores which, for all intents and purposes, can be used in memories if a sufficient number of cores having similar characteristics can be segregated into a group for the purpose of employment in a single memory plane. Of course, the test equipment shown may be employed for this purpose by changing the limits used after each run of a large number of cores and for each succeeding run using the cores which were rejected to obtain a separate group of cores. Thus, a memory can be fabricated from each group of cores, if desired. In View of the small size of the cores, the problem presented after testing the cores was how to separate them into the various groups.

An object of the present invention is to provide apparatus capable of segregating small articles such as cores and the like into a number of different groups.

A further object of the present invention is the pro vision of apparatus for segregating magnetic cores into a large number of substantially uniform classes.

Still a further object of the present invention is to provide separation mechanism which is novel and unique and which is employable with small objects.

These and further objects of the invention are provided in a magnetic core testing machine of the type described wherein provision is made for passing cores which have been tested through a passage having spaced openings in the walls. Containers are mounted at these openings at the various spaced positions along said walls. The cores which lhave been tested are either blown or deflected into these containers in accordance with their characteristics as determined from the test. Accordingly, at the end of a single pass through a large number of cores, each container will contain cores having substantially similar characteristics.

The novel features that are considered characteristic of this invention are set forth with particularity inthe appended claims. The invention itself, both as to its or- Figure 4 shows an embodiment of the invention wherein a core is deected into a container; and

Figure 5 is a cross section of an alternative embodiment of the invention. t

Referring now to Figure l, the magnetic core testing equipment includes a syntron elevator which is a commercially purchasable item. This has on its top a pot-shaped receptacle 10 designated as feeder in the drawings. The inside of the receptacle consists of an open pot having a spiral track around the side of its inner wall. The track is substantially one core wide and spirals up to a feeding ramp 14. The elevator 12 vibrates the feeder in a manner to throw the cores` against the outside of the pot feeder so that they move upwardly along the spiral track and onto and down the ramp 14. At the end of the ramp there is shown a wheel 16 having pins ltlextending radially therefrom. Four pins are shown, but, ofcourse, the number shown is by `way of example. This is similar to the apparatus shown in Figure 4 of the above-referred to article.

The pins 18 successively pass under the ramp. The end of the ramp is slotted and the wheel is positioned sothat the pins pass into the-slot in a manner to engage one of the torroidal cores being* held there. The core settles down on the pin toward the periphery of the wheel. As the wheel rotates the pin passes through a Zone which is ldefined by wire contacts 20. These wire contacts are in two sets one of which is arranged to pass current through the pin which electively acts as a one-turn coil through the core being tested. The program of the current pulses applied may be varied in accordance with the characteristics for which a test is desired. The other set of contacts serves to pick up the voltage induced when the core is driven. These voltages are read and a determination is made therefrom. These determinations are whether the core should be rejected or should be put in one of a number of classes with other cores having similar characteristics. The source of exciting voltages and the electrical equipment making the determinations are represented in the drawing by the rectangle 22 labeled selecton The wheel 16 is driven by an electric motor 24. The motor has a shaft 26 which drives a belt 28 which in turn drives a pulley 3l connected to the wheel 16 bearing the pins. When the magnetic core passes out from under the test zone, it then continues moving until it is over the group separation apparatus which is an embodiment of this invention. This is shown in Figure l as a passage 30 having a number of containers 32 attached thereto. Each container collects cores in a different core group.

When a pin bearing a core is over the passage, the corev4 will fall into the passage due to the force of gravity. Provision may be made to push the core off the pin into the passage with a slotted wiper, if required. Totally rejected cores fall into a container 33 at the bottom of the passage.

A timer 34 shown in Figure l is also driven from the motor and can consist of four separate cams corresponding to the four pins. These cams, among other timing operations, trip the selection mechanism at the proper interval when a core which has been tested drops oil the wheel into the selection passage.

Figure 2 is a simplied schematic diagram of core test equipment which is suitable for using this invention. Reading voltages from a core driven in accordance With the desired program are induced in the second set of contacts (not shown), designated as the reading coil.

A suitable arrangement of contacts is shown in Figure 4 y of the referred to article by Rajchman. Another arrangement, which is preferable, is shown, described and claimed in an application for Core-Testing Fixture by Raymond Stuart-Williams, filed August 9, 1954,V Serial Number 448,604, and assigned to this assignee.

The voltages induced in the reading coil are applied to an integrator and median setter 40 which integrates them and determines the median value. The output of the integrator and median setter is applied to an analog-to-digital converter 42 which serves to convert the amplitude of the Voltage to a digital number or a number of digital pulses. These digital pulses represent the characteristic of the tested core. They are applied to a solenoid selector matrix 44 which merely consists of a well-known circuit arrangement for selecting and exciting one out of many conductors whereby the proper solenoid 46 is excited. Thus, a digital number representing core characteristics is used to excite solenoids which, in conjunction with this invention, operate to separate tested cores into their proper groups having substantially similar characteristics. The timer 34 serves to reset the apparatus for each core undergoing test and to operate the solenoid 46 when the core which has been tested is dropped into the passage 30.

A cross section of an embodiment of the invention Cil is shown in Figure 3. As a core 48 drops through a passage 30, it passes by spaced openings in the walls in each of which a container 32 is tted. In the inner wall of the passage substantially opposite the opening for a container is a first door 52, which is connected to the wall at its upper end so that normally the door hangs down. A second door 50 is mounted by its upper end in the opening 51 in the passage wall which leads to the container. This door also hangs downward. ln this manner the core will fall through the passage and even though, due to vibration or other causes, it is deflected against an opening 51, it will not go through the opening into the container unless the door 50 is open. There is an opening 54 in the passage wall opposite the opening for the container. This opening serves to admit blast of air controlled from a solenoid 46. When a blast is not present, the core descends through the passage in the manner shown in Figure 3 by passing the various container openings. Upon a blast of air occurring, the door 5l) blocking olf the opening 51 is swung into it. The door 52 immediately below the air blast opening is drawn upward as a result of the low pressure air created by the rapid motion of the air blast area adjacent thereto. Thus, the core which is dropped into the selecting passage may hit the lower door and be prevented from dropping further and is blown into the specilic opening selected. The one of the solenoids selected acts to open an air valve and permit the air to be blown under pressure into the proper opening. The solenoid selector, as previously stated, serves to select the solenoid which actuates a valve to enable a core to be blown by a blast of air into a container having cores with similar characteristics. There are as many different solenoids and containers as there are different groups of cores. There is a container 33 at the bottom of the passage 30. This collects cores which do not fit into one of the dilerent groups.

In the embodiment of the invention shown in Figure 5, instead of air being blown under pressure, suction may be applied to a container. A door 56 serves the function of blocking off the entrance to a container. The length of the door is slightly in excess of the diameter of the selecting passage. The door is mounted at its bottom. Accordingly, as shown by the solid lines, the suction has the effect of pulling the door up to keep the opening to the container closed. Upon the proper selection, the suction is cut olf; the door falls by operation of gravity against the wall opposite the opening. Thus, a core strikes the door, as shown by the dotted lines, and is deected into the proper container.

Although the invention has been described as being operated by either air under pressure or suction, it is well within the skill of those versed in the art to operate these doors by other means such as mechanical connections to the doors which are solenoid or relay operated. Also7 the invention has been described in connection with separating cores into similar groups. It may also be used for separating other small articles of manufacture into groups and with other testing machines than the one shown.

Accordingly, there has been described and shown herein novel and useful selection apparatus for small articles of manufacture such as magnetic cores and the like which may be classified into different groups in accordance with their tested characteristics.

We claim:

l. In apparatus for testing magnetic cores, asserting mechanism comprising walls defining a vertical passage into which tested cores are dropped in succession, a plurality of vertically spaced openings along said walls, a plurality of containers each of which is attached to the outside of said walls at and in communication with a different one of said openings, a plurality of apertures in said walls each of which is opposite a different one of said openings, means to selectively blow air through said apertures to deflect a tested core into a predetermined one of said containers to collect cores in each of the containers having similar characteristics, and means at each spaced opening responsive to said blown air to close said passage to prevent said core from falling below the opening to said predetermined one of said containers.

2. Apparatus as recited in `claim 1 wherein said means at each spaced opening responsive to said blown air to close said passage includes a door which is swingably mounted to hang downward at the inside wall of said passage just below said aperture and which door is swung upward to close said passage upon air being blown through said aperture.

3. Apparatus as recited in claim 2 wherein there is included in addition in each opening a second door which is swingably mounted to hang downward inside said opening, said second door being swung upward to open said opening upon air being blown through the opposite aperture to permit a test core to be blown into the container attached thereat.

4. In apparatus for testing small articles such as magnetic cores and the like, asserting mechanism comprising walls defining a vertical passage into which tested articles are dropped in succession, a plurality of vertically spaced openings in said walls, a plurality of containers each of which is attached to the outside of said walls at and in 6 communication with a different opening, a rst plurality of doors each one of which is swingably mounted by an upper edge to hang downwardly along the inside wall of said walls opposite the lower edge of a dierent one of said openings, a second plurality of doors each one of which is swingably mounted by an upper edge to hang downwardly inside a dilerent one of said openings to close said one opening, and means to close said passage with the door mounted opposite the lower edge of the opening of a predetermined one of said containers and to deflect the door in the opening of said predetermined one of said containers to permit the deflection of a tested one of `said articles `into said predetermined container in accordance with the tested characteristics of said article.

References Cited in the file of this patent UNITED STATES PATENTS 1,572,809 Ratcliff Feb. 9, 1926 1,657,036 Remeur Ian. 24, 1928 1,946,307 Chambers Feb. 6, 1934 2,244,647 Broido June 3, 1941 2,468,843 Sunstein May 3, 1949 2,647,628 Diamond a. Aug. 4, 1953 2,796,986 Rajehman et al. June 25. 1957 

